Fluid-pressure brake.



W. V. TURNER.

FLUID PRESSURE BRAKE.

APPLIUATION FILED MAR. 39, 1909.

Patented Dec. 26, 1911.

WITNESSES INVENTOR COLUMBIA PLANCIGRAPH co wAsmNu'rpN. D c

irnn STATES PATENT onnron.

WALTER V. TURNER, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR TO-TI-IE WESTING-HOUSE AIR BRAKE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OFPENNSYLVANIA.

FLUID-PRESSURE BRAKE.

Specification of Letters Patent.

Patented Dec. 26, 1911.

To all whom it may concern: I

Be it known that I, WALTER V. TURNER, a citizen of the United States,residing at Edgewood, in the county of Allegheny and State ofPennsylvania, have invented new and useful Improvements in Fluid-Pressure Brakes, of which the following is a specification.

This invention relates to fluid pressure brakes, and more particularlyto an automatic device adapted to apply the brakes upon a suddenreduction in train pipe pressure when a hose bursts, cars pull apart, orother accident happens. A device of this character which is extensivelyemployed in service is shown in my prior Patent No. 882918 and in thisconstruction the brakes are normally operated in service by means of astraight air pipe through which air is supplied to and released from thebrake cylinder by manipulation of the motormans brake valve. A normallycharged train pipe is provided, a reduction of pressure in which isadapted to operate an emergency valve device to cut off communicationfrom the straight air pipe to the brake cylinder and to supply airdirectly to the brake cylinder. Where the brake is designed to supplythe full pressure of the system to the brake cylinder in an emergencyapplication so that there is no excess pressure available for chargingthe train pipe above normal in releasing the brakes, such as thebrakeshown in the above mentioned patent, in order to maintain the emergencyvalve parts in the normal release position and also to insure the fullreturn of the parts from emergency position to this normal position, ayielding resistance device or spring is employed. Occasionally thesesprings get broken, rust through, or otherwise become damaged, so as tointerfere with eflicient action of the emergency device.

Accordingly, the principal object of my present invention is to dispensewith springs in devices of the above character and it consists inproviding means adapted to be operated by fluid under pressure formaintaining the emergency valve parts in normal position.

In the accompanying drawing, Figure 1 is a diagrammatic view of acombined straight air and automatic emergency brake equipment for 'amotor car and trailer, showing my improvement applied thereto; Fig. 2 asimilar view of an electro-pneumatic brake equipment also showing myinvention applied; and Fig. 3 a vertical section of my improvedemergency valve device.

According to Fig. 1 of the drawing, my invention is applied to anequipment comprising a motormans brake valve 1, a main reservoir 2,supplied with air by a motor driven compressor 35 and connected to thebrake valve 1 by a pipe 3, emergency train pipe 4,.independent orstraight air pipe 5, and brake cylinder 6, on the motor car and on thetrailer car the equipment is similar, except that an auxiliary reservoir36 is employed for supplying air to operate the brakes instead of themain reservoir. The emergency valve device 7 is normally in a positionto maintain a free, open communication from the straight air pipe 5 tothe brake cylinder 6 and comprises a'slide valve 9' having a cavity 16for connecting brake cylinder pipe 13 with the straight air pipe 5 inthe normal inner position of the parts. The slide valve 9 is operated bya piston 10, the chamber at the outer face of which is in opencommunication with the emergency train pipe 4. The valve chamber 8 isconnected by a pipe 37 to the main reservoir 2 on the motor car or tothe auxiliary 36 on the-trailer car. As is the case with theconstruction shown in my prior Patent N 0. 882918, the brakes may beapplied and released in service by manipulation of the motormans brakevalve 1, through the straight air pipe 5 and cavity 16 in the slidevalve 9. The brakes are applied in emergency by turning the brake valveto a position for suddenly venting air from the train pipe 4, or bythe'bursting of a hose or the pulling apart of the cars of the train.The piston 10 of the emergency valve device on each car is then shiftedoutwardly and the slide valve 9 is actuated to cut off the straight airpipe 5 and open communication from the valve chamber 8 to the brakecylinder pipe 13. Air from the main reservoir or other reservoir is thenadmitted to the brake cylinder to apply the brakes with full force. Torelease the brakes, the train pipe pressure is increased to normalpressure by movement of the brake valve to release position and thefluid pressures on opposite sides of the piston 10 become equalized. Ifithis above mentioned prior patent a spring acting on the emergencypiston is employed for then returning the parts to and for maintainingthem in normal position. According to my present invention, I providethe inner end of the piston stem 17 with a piston head 18, the chamberat the outer face of which is in open communication through a pipe 19with the straight air pipe 5. It will now be evident that as thestraight air pipe 5'is open to the atmosphere in the release position ofthe brake valve, upon increasing the train pipe pressure to normal inthe usual manner in order to release the brakes there will be anunbalanced fluid pressure acting on the outer face of piston 10according to the area of the piston head 18, and thereby the parts arepromptly shifted to their normal inner position. v The piston head 18 ispreferably adapted to seat and make an air tight joint in its innerposition so as to prevent leakage of air from the valve chamber 8 to thestraight air pipe.

The improved emergency valve device may be applied to various othertypes of brake equipment such as an electro-pneumatic system, forexample, and in Fig. 2 of the drawing I have shown my improvementsapplied to an apparatus of this character. Instead of the straight airpipe, a pipe 40 is normally connected to the brake cylinder pipe by thecavity 16 of the slide valve 9 and a suitable electro-pneumaticmechanism is provided in the pipe 40 for controlling the admission offluid under pressure to and its release from the brake 1 cylinder, suchas a release magnet valve ll and an application magnet valve 42 having asupply pipe 43 connected to the main or other reservoir on the car, theusual train wires and contacts in the brake valves 44: being providedfor controlling the operation of the magnet valves. The brakes are thenapplied and released in service through the pipe 40 by the operation ofthe magnet valves 41 and 42 in the usual manner and an emergencyapplication is produced by a sudden reduction in train pipe pressure inthe same manner as described in connection with the construction shownin Fig. 1 of the drawing, as will be apparent. The pipe 19 beingconnected to the pipe 40, the piston head 18 is open to the atmospherethrough the release magnet valve 41, in release position of the brakeswitch, so that in releasing the brakes, the emergency valve mechanismis shifted to the normal release position upon increasing the pressurein the train pipe, and the parts are then maintained in this position bythe unbalanced train pipe pressure acting on the larger piston head 10.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is

1. An automatic valve device comprising a piston and valve meansoperating upon a reduction in train pipepressure for applying the brakesand fluid pressure operated means subject on one side to atmosphericpressure for returning the said piston and valve means to normal releaseposition.

2. An automatic valve device comprising a piston subject on one side totrain pipe pressure, valve means operated thereby for supplying air tothe brake cylinder, and a movable abutment normally subject on one sideto atmospheric pressure for maintaining theparts in normal releaseposition.

3. In a fluid pressure brake, the combination with a train pipe andbrake cylinder, of an emergency valve device comprising a piston havingdifferential piston heads subject in one direction to train pipepressure and in the opposite direction to atmospheric pressure andhaving the pressure of a reservoir acting between said piston heads andvalve means operated thereby for supplying air to the brake cylinder.

4. In a fluid pressure brake, the combination with a train pipe andbrake cylinder, of a valve device comprising valve means having a normalposition in which communication is open for applying and releasing thebrakes in service, a piston operated by a reduction in train pipepressure for cutting ofl' said communication and supplying air directlyto the brake cylinder, and a piston head subject on one side toatmospheric pressure for returning the parts to normal positionupon'increasing the train pipe pressure.

5. In a fluid pressure brake, the combina tion with a train pipe andbrake cylinder, of valve means for controlling the admission of fluidunder pressure to the brake cylinder, and an operating piston therefor,comprising diflerential heads subject in one direction to variations intrain pipe pressure in the opposite direotionito atmospheric pressureand to the pressure of fluid from a sub stantially constant sourceintermediate said heads. V

6. In a fluid pressure brake, the combination with a train pipe andbrake cylinder, of an automatic valve device having a normal positionestablishing a communication through which the brakes are applied andreleased in service and comprising valve means and 'a differentialpiston subject in one direction to train pipe pressure'and in theopposite direction to pressure from a substantially constant source andT atmospheric pressure.

V 7. In a fluid pressure brake, the combination with a train pipe, brakecylinder, and main reservoir, of a service application and release pipe,an automatic valve device nor-.

mally establishing communication from said application and release pipeto the brakecylinder and comprising valve means and an operating pistonhaving difi'erential heads, one subject to the opposing pressures of thetrain pipe and main reservoir and the other normally subject on one sideto a different pressure.

8. In a fluid pressure brake, the combina tion With a train pipe, brakecylinder, straight air pipe and main reservoir, of an automatic valvedevice having a normal position connecting the brake cylinder vvith thestraight air pipe and comprising valve means and an operating pistonhaving differential heads one subject to the opposing pressures of thetrain pipe and main reservoir and operating upon a reduction in trainpipe pressure for cutting 0E said communication and supplying air fromthe main reservoir to the brake cylinder and the other subject toatmospheric pressure for return- "ing the parts to normal position uponan increase in train pipe pressure.

9. In a fluid pressure brake, the combination with a train pipe, of anautomatic valve device having a differential piston subject on one sideto train pipe pressure and valve'means operated by said piston foreffecting an emergency application of the brakes at the full pressure ofthe brake system and means for venting air from one face of said pistonto thereby shift same to release position upon increasing the train pipepressure.

In testimony whereof I have hereunto set my hand.

WALTER V. TURNER.

Witnesses WM. M. GADY, A. M. CLEMEN'rs.

Copies of this patent may be obtained for five cents each, by addressingthe "Commissioner of Patents, Washington, D. G.

